Evaluation of ventricular function and myocardial deformation in children with repaired tetralogy of Fallot by real-time three-dimensional (four-dimensional) echocardiography

Aim: The left and right ventricular dysfunction are important clinical course indicators in patients with repaired tetralogy of Fallot. This study aimed to evaluate ventricular volumes, functions, and myocardial deformation in children with repaired tetralogy of Fallot by real-time three-dimensional (four-dimensional) echocardiography and compared with healthy children. It also aimed to investigate the relationships between ventricular volumes, functions, and myocardial deformation parameters in the patients. Materials and methods: In this cross-sectional study, 35 patients (mean age 15.1 ± 2.8 years, 54% male) and 35 healthy controls of similar age, gender, and body measurements underwent echocardiography. End-diastolic volume index, end-systolic volume index, and ejection fractions of both ventricles; global longitudinal, circumferential, radial strain, twist, and torsion of the left ventricle; the longitudinal strain of the right ventricle free wall and septum were measured. Results: Left ventricular ejection fraction, global circumferential and radial strain, twist and torsion were significantly lower in patients compared with controls. Left ventricular ejection fraction correlated with global circumferential (r = −0.446, p < 0.001) and radial strain (r = −0.433, p < 0.001) in the patients. Right ventricular volumes were significantly higher, and ejection fraction was significantly lower in patients compared with controls. All right ventricular parameters correlated with each other in the patients. Conclusion: Left ventricular contraction pattern was changed, circumferential and radial fibres were most affected in the patients. Right ventricular dilatation and dysfunction were detected, and right ventricular ejection fraction correlated well with strain measurements of the right ventricle.

Non-Invasive Quantification of Pressure-Volume Loops in Patients with Fontan Circulation

BackgroundPressure-volume (PV) loops provide comprehensive information of cardiac function, but commonly implies an invasive procedure under general anesthesia. A novel technique has made it possible to non-invasively estimate PV loops with cardiac magnetic resonance (CMR) and brachial pressure which would enable good volume estimation of often anatomically complex ventricles without the need of anesthesia in most cases. In this study we aimed to compare how hemodynamic parameters derived from PV loops in patients with Fontan circulation differ to controls. Methods Patients with Fontan circulation (n=17, median age 12 years, IQR 6-15) and healthy controls (n=17, 14 years, IQR 13-22) were examined with CMR. Short axis balanced steady-state free-precession (bSSFP) cine images covering the entire heart were acquired. PV loops were derived from left ventricular volumes in all timeframes and brachial blood pressure from cuff sphygmomanometry. ResultsPatients had lower stroke work, ventricular mechanical efficiency and external power compared to controls. Patients with dominant right ventricle (RV) had higher potential energy indexed to body surface area (BSA) but lower contractility (Ees) compared to controls. Patients had higher arterial elastance (Ea) and Ea/Ees ratio than controls. No difference was seen in energy per ejected volume between patients and controls.ConclusionsThis non-invasive PV-loop method could be used in future studies to show the potential prognostic value of these measures and if changes in ventricular function over time can be detected earlier by this method compared to changes in ventricular volumes and ejection fraction (EF). In contrast to patients with acquired heart failure, Fontan patients had similar energy per ejected volume as controls which suggests similar ventricular oxygen consumption to deliver the same volume in Fontan patients as in controls.

Prediction of persistent ventricular dilation by initial ventriculomegaly and clot volume in a porcine model

OBJECTIVE While intraventricular hemorrhage (IVH) is associated with posthemorrhagic ventricular dilation (PHVD), not all infants affected by high-grade IVH develop PHVD. The authors aimed to determine clot-associated predictors of PHVD in a porcine model by varying the amount and rate of direct intraventricular injection of whole autologous blood. METHODS Seven 1-week-old piglets underwent craniectomy and injection of autologous blood into the right lateral ventricle. They survived for a maximum of 28 days. MRI was performed prior to injection, immediately postoperatively, and every 7 days thereafter. T1-weighted, T2-weighted, and susceptibility-weighted imaging (SWI) sequences were used to segment ventricular and clot volumes. Spearman correlations were used to determine the relationship between blood and clot volumes and ventricular volumes over time. RESULTS The maximum ventricular volume was up to 12 times that of baseline. One animal developed acute hydrocephalus on day 4. All other animals survived until planned endpoints. The interaction between volume of blood injected and duration of injection was significantly associated with clot volume on the postoperative scan (p = 0.003) but not the amount of blood injected alone (p = 0.38). Initial postoperative and day 7 clot volumes, but not volume of blood injected, were correlated with maximum (p = 0.007 and 0.014) and terminal (p = 0.014 and 0.036) ventricular volumes. Initial postoperative ventricular volume was correlated with maximum and terminal ventricular volume (p = 0.007 and p = 0.014). CONCLUSIONS Initial postoperative, maximum, and terminal ventricular dilations were associated with the amount of clot formed, rather than the amount of blood injected. This supports the hypothesis that PHVD is determined by clot burden rather than the presence of blood products and allows further testing of early clot lysis to minimize PHVD risk.

Energetic cost of walking and Brain Atrophy in Mid-to-Late Life

Background Higher energetic costs for mobility are associated with declining gait speed and slow gait is linked to cognitive decline and Alzheimer’s disease. However, the physiological underpinnings of gait and brain health have not been well explored. We examined the associations of the energetic cost of walking with brain volume in cognitively unimpaired adults from the Baltimore Longitudinal Study of Aging. Methods We used brain MRI data from 850 participants (mean baseline age 66.3±14.5 years), of whom 451 had longitudinal MRI data (2.8±1.0 MRI scans over 4.0±2.0 years). The energetic cost of walking was assessed as the average energy expended (V̇O2) during 2.5 minutes of customary-paced overground walking. Multivariable linear mixed effects models examined the associations between baseline energetic cost of walking and regional brain volumes adjusting for covariates. Results At baseline, higher energetic cost of walking was cross-sectionally associated with lower gray and white matter volumes within the frontal, parietal, and temporal lobes, as well as hippocampal, total brain, and larger ventricular volumes (all FDR p&lt; 0.05). A baseline energetic cost of walking × time interaction demonstrated that participants with higher energetic cost of walking had faster annual decline in hippocampal volume (FDR p= 0.01) and accelerated annual increase in ventricular volumes (FDR p= 0.01). Conclusions The energetic cost of walking is associated with gray and white matter volumes and subsequent hippocampal atrophy and ventricular enlargement. Collectively, these data suggest the energetic cost of walking may be an early marker of neurodegeneration that contributes to the gait brain connection.

Intraparenchymal hemorrhage after serial ventricular reservoir taps in neonates with hydrocephalus and association with neurodevelopmental outcome at 2 years of age

OBJECTIVE Decompressing the ventricles with a temporary device is often the initial neurosurgical intervention for preterm infants with hydrocephalus. The authors observed a subgroup of infants who developed intraparenchymal hemorrhage (IPH) after serial ventricular reservoir taps and sought to describe the characteristics of IPH and its association with neurodevelopmental outcome. METHODS In this multicenter, case-control study, for each neonate with periventricular and/or subcortical IPH, a gestational age-matched control with reservoir who did not develop IPH was selected. Digital cranial ultrasound (cUS) scans and term-equivalent age (TEA)–MRI (TEA-MRI) studies were assessed. Ventricular measurements were recorded prior to and 3 days and 7 days after reservoir insertion. Changes in ventricular volumes were calculated. Neurodevelopmental outcome was assessed at 2 years corrected age using standardized tests. RESULTS Eighteen infants with IPH (mean gestational age 30.0 ± 4.3 weeks) and 18 matched controls were included. Reduction of the ventricular volumes relative to occipitofrontal head circumference after 7 days of reservoir taps was greater in infants with IPH (mean difference −0.19 [95% CI −0.37 to −0.004], p = 0.04). Cognitive and motor Z-scores were similar in infants with and those without IPH (mean difference 0.42 [95% CI −0.17 to 1.01] and 0.58 [95% CI −0.03 to 1.2]; p = 0.2 and 0.06, respectively). Multifocal IPH was negatively associated with cognitive score (coefficient −0.51 [95% CI −0.88 to −0.14], p = 0.009) and ventriculoperitoneal shunt with motor score (coefficient −0.50 [95% CI −1.6 to −0.14], p = 0.02) after adjusting for age at the time of assessment. CONCLUSIONS This study reports for the first time that IPH can occur after a rapid reduction of the ventricular volume during the 1st week after the initiation of serial reservoir taps in neonates with hydrocephalus. Further studies on the use of cUS to guide the amount of cerebrospinal fluid removal are warranted.